Safety device for elevators



(No Model.)

W. P. KIDDER. SAFETY DEVICE FOR ELEVATORS.

No. 525,421. Patented se i 4, 1894-.

UNITED STATES PATENT OFFICE.

W ELL'INGTON P. KIDDER, OF BOSTON, MASSACHUSETTS.

SAFETY DEVICE FOR ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 525,421, dated September 4, 1894.

Application filed August 22, 1893. Renewed August 8, 1894. Serial No. 519,774. (No model.)

To all whom it may concern.-

Be it known that I, WELLINGTON P. KID- DER, a citizen of the United States of America, residing at Boston, in the county of Sufiolk and State of Massachusetts, have invented certain new and useful Improvements in Safety Devices for Elevators, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention is designed more particularly as an improvement on the safety devices shown in my Patent No. 495,094 and my application, Serial No. 473,780, filed May 11, 1893, but it may be applied in part to other elevators.

In mostall power elevators, it is found to" be important to provide stops on the rope near the top and bottom thereof, which are engaged by the elevator in case the-operator fails to stop the car at its extreme upward or downward motion; which is very necessary, as otherwise the motion of the car would continue and the car rise so high or descend so low as to do great damage. The use of these stops causes the car, when it reaches a certain point in its motion in either direction, to move the rope and thus stop the car, but it often happens with some elevators that the momentum of the car moves the rope too far so far in fact as to open the valve and start the car in the opposite direction, so that the car might thus travel up and down continuously until the power was stopped or the rope properly adjusted by hand. Besides this difficulty there is another one which will occur where my safety stops are used. If the car moves the rope too far to stop, it would carry my safety stop entirely past the opening between the horizontal bars on the door, and if any one just at the moment when the stop was thus passing, tried to open thedoor, my

' stop might be caught by the bars on the door and thus damage would result. To overcome these difficulties is the object of my improvement, and to this end the invention consists in the construction, arrangement and combilarger scale.

parts thereof. Fig. 2 is a modification on a Referring now to the details of the drawin gs by letter, A represents the well of an elevator, B one of the doors thereof, 0 the car and D the operating or controlling rope thereper block is shown a spiral spring F, wound open, and above the lower one is a similar spring. The upper spring should be mounted so as not to fall down, which may be done by attaching it to the block E in any convenient way. These springs may be attached to the top and bottom of the car and travel with it if preferred, but I consider it best to connect .if the momentum of the car should be so great as to be sufficient to carry the car too far, then, in case the controller is arrested from any cause so that the block E could not go any higher, then if the momentum of the car continues, the spring will be compressed and no injury would result therefrom. In some cases, I may attach a spring (shown indotted lines at I) to the under side of the beam, in which case the block E would come in contact with the spring if carried too far up by the momentum of the car and thus said spring I would-act as a bufier. This spring I may be used either with or without the spring F.

To overcome the other difficulty referred to, I propose to make a yielding connection be tween the controller and my rope-stops. One .of the best ways of carrying out this feature I of my invention is that shown in the drawings, but I do not wish to limit myself to this, asit may be done in various ways.

Referring again to the drawings: J-represents a supplementary rope carrying the safety stop K, which is preferably fast thereon and cooperates with the bars 17 and b, as in my application No. 473,780. This rope passes around suitable pulleys L and its opposite ends are preferably attached to closely Wound springs M whose other ends are attached to the stops E, or to any convenient portions of the controller. Should the car now carry the block above its proper height, and an attempt be made to open the well door at. the time that the safety rope-stop K is passing the opening between the bar-stops, so that the stop would be partly entered into the open-- 1 ing, the spring connection M, between the safety rope-stop K and the block E, would yield and thus no damage result. Asia further precaution, I cut oi the corners at the junction. of the horizontal and vertical bars diagonally or slantingly as shown, so that should the-door not be closed. far enough. to

be latchedflthe stop pushing against such diagonal corner would push the door fully homefand thus the=latch would catch fast. Instead of. the spring connection between the rope J and the stop K, I may sometimes loosely mount the safety-stop on the rope'J between springs N, as shown: in Fig. 2. In this case if. there should beany improper motion given to the rope J at a time when the stop. K was betweenthe horizontal door stops,

the springs would yield and thus damage the controller and car thereof, a door, and a would be prevented.

Of course. the springs M or N should be;

sufficiently strong. as not to be operated by hand, or otherwise they might be used in such. a manner as to entirely defeat the object of my safety stop.

In some cases instead. of. using springs,.I may attach the stop K by a frictional connection, so that should there be any extra strain it. would slide on the rope J, but this 1 the controller, a. door, and the car thereof, a

would not be so good as the other arrangements described, inasmuch as after sliding on the rope the stop would require to be adjusted to its proper position.

In. addition to the advantages above set forth, the supplementary rope J above described has the further advantage that it forms a. very convenient way of attaching my safety device to elevators already in use, for it frequently happens that the ordinary controller. or rope is not in a position to con.- veniently receive the safety stops, and cannot well be changed in. such a manner as to hold the stops in the proper position to act on the door.

I have used the beam supporting the pulleys and controller in the arrangement first described above, as a stop to prevent the block E from rising too high, but of course any other fixed part of the frame may be usedlasa stop for said block. Instead of the block,a pin passingthrough therope at. right. angles and. properly secured may be used. Other forms of stops may perhaps be used with as good advantage, but I prefer a block,

and when I mention a block in the following claims, I mean to include any known device that will serve the same function, the word block being used here to more clearly distinguish it from stops co-acting with the doors. These spring connections may also be used with any other form of controller as well as with the. rope controller shown.

In some cases, the springs or bumpersF may sufficiently protect my safety stop and door mechanism from injury, in which case the springs M or their equivalents may not be required.

I-n-the drawings I have shown my safety rope-stop K acting upon the door through the mediumof horizontal and vertical bars I) and b, but do notlimit myself to this arrangement- Intthe following claims, when I- refer to coacting or engaging. with the door, I'wish to be understood as meaning. any arrangeintermediate mechanism.

What I. claim as new is 1. In. an elevator and in. combination. with the controller and car thereof of ablock on the controller acted on by the car, and a spring co'acting therewith, substantially as described.

2. In an elevator and in. combination with stop to engage with the door yieldingly connected with the.controller,substantially as described.

3. In an elevatorand in combination with the controlling rope, a door and the car thereof,

a supplementary stop-carrier connected with the controlling rope and having stops co-acting with the door,substant-ially as described. 4. In an elevator and in combination with supplementary stop-carrier connected with the controller, and a spring connection between the controller and the stop carrier, substantially as described.

5. In an. elevator and in combination with the controlling rope, a door, and the car thereof, a supplementary stop-carrier, a block ,on the controlling. rope, and a spring connection between the block. and supplementary rope-carrier, substantially as described.

6. In an elevator and in combination with the controller and the car thereof, astopcon- WELLINGTON P. KIDDER.

Witnesses:

P. B. RISMAN, M. P. EVANS.

IOC 

